Search

Purpose: To identify factors that influence Black women’s body size perceptions Design: Interviews (cognitive mapping exercise) with 25 women; focus group with 7 additional women Setting: Mississippi Delta Participants: Thirty-two black women Measures: Influences on body size perceptions, body mass index, and body satisfaction Analysis: Interviewee maps were combined and condensed, using matrix addition and qualitative aggregation, to create a social map. The social map was presented to a focus group. A paired sample t test and descriptive statistics were run to assess weight perception accuracy and body satisfaction. Results: The initial social map contained 27 variables. Male preferences (87.5%) and appearance (64%) were believed by most participants to influence perceptions of body size. The focus group identified lack of encouragement, stress, and substance use as factors worth adding to the map. A statistically significant proportion of interviewees possessed an inaccurate weight perception, t(24) = 2.741, P < .05. Furthermore, 76% were dissatisfied with their current weight status and 80% desired a healthy body size. Conclusion: These findings provide practitioners with leverage points, beyond diet and physical activity, that may improve the efficacy of weight reduction interventions among black women. Considering the paucity of research regarding influences on body size perceptions, this study also provides researchers with participant-defined variables worthy of further examination.

Context: Studies developed the frail elderly handgrip strength (HGS) diagnostic criteria using multiple types of handgrip dynamometers. If different handgrip dynamometers report different values, then this would have the potential to misclassify people into the wrong diagnostic category. Objective: To examine the characteristics of HGS measured by 2 standard handgrip dynamometers and to investigate the influence of hand size on HGS. Setting: University research laboratory. Participants: A total of 87 young and middle-aged adults between the ages of 20 and 60 years participated in this study. Main Outcome Measures: Standard methods of HGS measurements were used for hydraulic and Smedley spring-type dynamometers, although the participants were instructed to maintain an upright standing position in both tests. Results: Test–retest reliability of hydraulic and Smedley dynamometers provided comparable results to that observed with previous studies. However, the difference in HGS between the 2 dynamometers (Hydraulic–Smedley difference) was positively associated (r = .670, P 45 kg) produced greater strength values with the hydraulic compared with the Smedley. The hand and palm lengths were weakly correlated (r = .349 and r = .358, respectively, both Ps Conclusions: Test–retest reliability of hydraulic and Smedley dynamometers provides comparable results to previous studies. However, the difference in HGS between the 2 dynamometers was positively associated with the mean of the 2 dynamometers. This Hydraulic–Smedley difference would not affect persons who have relatively low HGS (at least

Functional limitations persist in obese patients after total knee arthroplasty (TKA). This study assessed the effect of an exercise program (EP) and fitness trackers (FT) in obese patients with TKA. Sixty patients 1 year after orthopedic surgery were recruited and received a 16-week tailored EP; half were randomized to receive an FT. FT had no measurable effect compared with EP alone. EP improved knee range of motion, strength, and quality-of-life scores. This study provides preliminary evidence that a 16-week EP in obese individuals 1 year post TKA is feasible and effective in improving function and quality of life.

Obese patients are more likely to have osteoarthritis and total knee arthroplasty (TKA). This investigation sought to evaluate physical function, activity level, and quality of life (QOL). Obese participants near 1-year postsurgical follow-up appointment were recruited. Evaluation included QOL and activity questionnaire, medical histories, anthropometrics, strength, and aerobic capacity. Sixty participants completed assessments. Obese TKA patients have physical performance limitations and low physical activity levels 1 year after surgery and completion of postoperative rehabilitation.

To test the validity of published equations, 79 Caucasian adults (40 men and 39 women) aged 50–78 y had muscle thickness (MT) measured by ultrasound at nine sites of the body. Fat-free mass (FFM), lean soft tissue mass (LM) and total muscle mass (TMM) were estimated from MT using equations previously published in the literature. Appendicular LM (aLM) was estimated using dual-energy X-ray absorptiometry (DXA) and this method served as the reference criterion. There were strong correlations (range r = 0.85–0.94) between DXA-derived aLM and estimated FFM, leg LM or TMM. Total error between DXA-derived aLM and TMM (∼2 kg) was lower compared with the three other selected equations (6–10 kg). A Bland-Altman plot revealed that there was no systematic bias between aLM and TMM; however, the other three equations included systematic error. Our results suggest that an ultrasound equation for TMM is appropriate and useful for evaluating skeletal muscle mass in the body.

It is unknown whether age-related site-specific muscle loss is associated with areal bone mineral density (aBMD) in older adults. To examine the relationships between aBMD and whole-body muscle thickness distribution, 97 healthy adults (46 women and 51 men) aged 50-78 years volunteered. Total and appendicular lean soft tissue mass, aBMD of the lumbar spine (LS-aBMD) and femoral neck (FN-aBMD) were determined using dual-energy X-ray absorptiometry. Muscle thickness (MT) was measured by ultrasound at nine sites of the body (forearm, upper arm, trunk, upper leg, and lower leg). Relationships of each co-variate with aBMD were tested partialling out the effect of age. aBMD was not correlated with either MT of the trunk or anterior lower leg in either sex. In men, significant and relatively strong correlations were observed between anterior and posterior upper arms, posterior lower leg, and anterior upper leg MT and LS-aBMD or FN-aBMD. In women, significant correlations were observed between anterior and posterior upper legs, posterior lower leg, and anterior upper arm MT and FN-aBMD. LS-aBMD was only correlated with forearm and posterior upper leg MT in women. In conclusion, the site-specific association of MT and aBMD differs between sexes and may be associated with the participants' daily physical activity profile.

To develop regression-based equations for estimating dual-energy x-ray absorptiometry (DXA) derived appendicular fat-free adipose tissue (FFAT) using a single ultrasound image in the forearm, and to investigate the validity of those equations to calculate FFAT-free appendicular lean mass (aLM-minus-FFATSubjects were randomly separated into two groups: 215 in the model-development group (91 men and 124 women) and 96 in the cross-validation group (42 men and 54 women). Appendicular fat mass and aLM were measured by the DXA, and subcutaneous adipose tissue (AT-forearm) and muscle (MT-ulna) thicknesses were measured by ultrasound. Appendicular FFAT was calculated based on the results of a previous study (appendicular FFAT = appendicular fat mass/0.85 x 0.15). The aLM was estimated from MT-ulna using a previously published equation (aLM = 4.89 x MT-ulna x body height - 9.15). Stepwise linear regression analysis was used to determine predictive models for DXA-derived appendicular FFAT from AT-forearm, sex, age, and anthropometrical variables. The best ultrasound prediction equation for estimation of appendicular FFAT was developed and then cross-validated in a subsample of older adults.There was no significant difference between the DXA-derived and ultrasound-predicted aLM-minus-FFATOur results indicated that a single ultrasound forearm measurement can be used to accurately estimate DXA-derived aLM-minus-FFAT

The purpose of this study was to examine changes in physical activity and fitness variables in members of 8 volunteer families after 3 months of home use of the Wii Fit™ interactive video game. Pre and postintervention measurements were obtained from 21 subjects relative to physical activity (5 days of accelerometry), aerobic fitness (graded treadmill test), muscular fitness (push-ups), flexibility (sit-and-reach test), balance (composite equilibrium score), and body composition (body mass index and % body fat). Use characteristics of the Wii Fit™ device were also determined. A series of 2 (age group) × 2 (time) repeated measures analyses of variance were conducted to assess changes over time and between adults and children. Three months of home Wii Fit™ use revealed no significant age group × time interactions or main effects of group or time for daily physical activity, muscular fitness, flexibility, balance, or body composition. An age group × time interaction (p = 0.04) was observed in peak VO2 (ml·kg(-1)·min(-1)) with children displaying a significant (p = 0.03) increase after 3 months of Wii Fit™ use, whereas adults showed no significant (p = 0.50) change. Daily Wii Fit™ use per household declined by 82% (p < 0.01) from 21.5 ± 9.0 min·d(-1) during the first 6 weeks to 3.9 ± 4.0 min·d(-1) during the second 6 weeks. Most measures of health-related fitness in this exploratory study remained unchanged after 3 months of home use of the popular Wii Fit™ whole-body movement interactive video game. Modest daily Wii Fit™ use may have provided insufficient stimulus for fitness changes.

The purpose of this study was to compare heart rate peak in obese (n=43) and normal weight (n=45) female youth. Heart rate (HR) peak was significantly lower (p2 (L min-) peak similar between groups (1.77±20.53, 1.97±0.60). Bivariate correlations for heart rate peak with body weight, percent fat, and body mass index yielded the following: -0.53, -0.54, and -0.57. These findings agree with the adult data indicating low HR peak in obese individuals. Further research is needed to explore physiologic factors that may lead to reduced HR peak in obese female youth.

The aim of the study was to objectively determine whether the Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) program improved physical activity levels during the school day.The study compared the physical activity levels of subjects from 26 daycare centers, randomized into treatment (N=13) and control (N=13) groups. The subjects were 3 to 5 year olds (N=209, 104 males and 105 females; age [years]=3.85±0.8 [mean±standard deviation]), and accelerometry was used to determine the subjects' physical activity levels. Accelerometers were attached to each subject for 2 days before and immediately after a 6-month intervention. Height, mass, and waist were also measured.Regression analyses indicated that the treatment group demonstrated significant increases in moderate and vigorous physical activity, as compared to the control group (F(1, 207)=6.3, p0.05, Cohen's d=0.30; F(1, 207)=4.7, p0.05, Cohen's d=0.25, respectively). The treatment group also showed significant increases in total physical activity (F(1, 218)=12.4; p0.05) from pre- to post-test with significant increases in moderate and vigorous intensity physical activity (F(1, 218)=18.6, p0.05; F(1, 218)=23.3, p0.05, respectively). Regression analyses revealed significant increases in height for both groups from pre- to post-tests, but no differences were noted between groups.Implementation of the NAP SACC program in treatment daycare facilities resulted in significant increases in objectively measured physical activity levels, compared to the control group, demonstrating physical activity improvement in the treatment daycare centers.

AB Purpose: Childhood cancer survivors (CCS) experience late effects that interfere with physical function. Limitations in physical function can affect CCS abilities to actively participate in daily activities. The purpose of this investigation was to evaluate the concordance between self-reported physical performance and clinically evaluated physical performance among adult CCS. Methods: CCS 18 yr or older and 10 yr or older from diagnosis who are participants in the St. Jude Lifetime cohort study responded to the physical function section of the Medical Outcome Survey Short Form (SF-36). Measured physical performance was evaluated using the Physical Performance Test and the 6-Minute Walk Test. Results: Individuals (N = 1778, 50.8% female) with a median time since diagnosis of 24.9 yr (range = 10.9-48.2) and a median age of 32.4 yr (range = 19.1-48.2) completed testing. Limitations in physical performance were self-reported by 14.1% of participants. The accuracy of self-report physical performance was 0.87 when the SF-36 was compared with the 6-Minute Walk Test or the Physical Performance Test. Reporting inaccuracies most often involved reporting a physical performance limitation. Poor accuracy was associated with previous diagnosis of a bone or CNS tumor, lymphoma, older age, and large body size. Conclusions: These results suggest that self-report, using the physical performance subscale of the SF-36, correctly identifies CCS who do not have physical performance limitations. In contrast, this same measure is less able to identify individuals who have performance limitations.

OBJECTIVE The conventional ratio method (milliliters O(2) per mass) typically is used to express VO(2) peak. The goal of the current study was to compare VO(2) peak of obese girls with normal-weight girls by ratio and allometric scaling methods. RESEARCH METHODS AND PROCEDURES We compared VO(2) peak by ratio and allometric methods in 46 obese and 47 normal-weight girls. Indirect calorimetry was used to measure VO(2) peak during either treadmill running or walking. Regression analysis was used to determine coefficients for mass and stature for each group with ANOVA used to compare data between groups. RESULTS The obese girls were taller and had higher values of body fatness (p < or = 0.05). Absolute VO(2) peak (liters per minute) was similar between groups; however VO(2) peak relative to mass was 50% lower (p < or = 0.05) in the obese girls. When VO(2) peak (milliliters per minute per kilogram) and mass were correlated, r = -0.48 was found in the obese group. Allometric scaling of logarithmic transformed stature and mass reduced this to r = -0.002, thus eliminating the bias associated with the ratio method. Adjusting VO(2) peak allometrically scaled for mass, stature, and the combination of mass and stature reduced the difference between groups from 50% (ratio method) to 10% to 11% (p < or = 0.05) with higher values found in the normal-weight girls. DISCUSSION These results demonstrate the bias associated with the ratio method when comparing VO(2) peak in obese girls with VO(2) peak in normal-weight girls. Allometric scaling eliminated the bias and thus may reflect a truer comparative response.

Background: Safe and effective exercise programs are needed to prevent and treat chronic diseases in childhood. In particular, preadolescent obese children should participate in activities that are specific to their special needs. Resistance or strength training has been prescribed for adult obese persons. Research is limited concerning the use of resistance training in programs that treat obese preadolescents. Methods: Nineteen treatment subjects (7-12 years of age) were enrolled in a 1 O-week weight management program which included diet, behavior modification, and aerobic and flexibi lity exercises. Forty-eight control subjects (7-12 years of age) participated in the diet, behavior modification program, and a thrice-a-week walking program. The efficacy of the overall weight management program was examined by anthropometry at 10 weeks and 1 year. Results: Fifteen treatment subjects completed the 10-week program (retention rate, 78.9%). Thereafter compliance decreased by approximately 33% for the long-term study. Seventeen control subjects completed the program (retention rate, 35%). Weight, percent of ideal body weight, and body mass index were reduced significantly at 10 weeks (P and did not increase significantly at 1-year follow-up in both treatment and control groups. Height increased significantly at 1 year in both treatment and control subjects. In the treatment subjects, percent fat decreased significantly (p P > 0.05). Conclusions: A resistance-training program may be included safely in a multidisciplinary weight management program for obese preadolescent male and female children. The addition of specific exercise regimes such as resistance training may improve program retention especially in severely obese youth.

To test the hypothesis that static balance is associated with site-specific loss of muscle mass in older adults.A total of 57 active women aged 52-83 years had their muscle thickness (MTH) measured by ultrasound at four sites on the anterior and posterior aspects of their upper- and lower-leg. MTH ratios were calculated to assess the site-specific muscle loss. One-leg standing balance with eyes open and maximum isometric knee extension/flexion strength were measured. Daytime physical activity was also measured. The participants were separated into three groups based on achieved timed one-leg balance test: less than 60 s (n = 19, G1), 60-120 s (n = 12, G2) and over 120 s (n = 26, G3).Age was inversely correlated to the upper-leg (A50 : P70) MTH ratios (r = -0.389, P 0.001), but not lower-leg ratio (r = 0.047), thus site-specific muscle loss was observed in the upper-leg. Total muscle mass was similar among the groups. A50 : P70 MTH ratio and absolute and relative knee flexion strength were lower in G1 than in G3. Step counts and durations of moderate and vigorous exercise were lower in G1 and G2 than in G3. There were significant correlations between one-leg balance and A50 : P70 MTH ratio (r = 0.271, P 0.05) and physical activity level (r = 0.357-0.481, P 0.01). After adjusting for step count, one-leg balance was only correlated significantly with duration of vigorous exercise (r = 0.319, P 0.05).Higher physical activity could have more impact on balance regulation, as the influence of site-specific muscle loss was weak in active women.

The purpose of this study was to compare the prevalence of severe sarcopenia detected by total skeletal muscle mass (SM) index and of site-specific thigh sarcopenia for differing age groups in men and women. Japanese nonobese men and women aged 20 to 85 (n = 1,994, 55 % women) had muscle thickness (MTH) measured by ultrasound at six sites on the anterior and posterior aspects of the body. SM was estimated from ultrasound-derived prediction equations. Site-specific thigh sarcopenia was calculated using ultrasound-measured MTH at the anterior and posterior aspects of the thigh (MTH ratio, anterior 50 %/posterior 50 % thigh MTH (A50/P50 MTH)). Sarcopenia was defined as a SM index (SM divided by height2) of >2 standard deviations (SD) below the mean for young adults. Site-specific thigh sarcopenia was defined as a ratio of A50/P50 MTH of >2 SD below the mean for young adults. Age was inversely correlated to SM index and A50/P50 MTH in men (r = −0.480 and r = −0.522) and women (r = −0.243 and r = −0.516). The prevalence rate of sarcopenia was less than 3 % for women under the age of 60, 7 % for ages 60–69, and 24 % for ages 70–80. In men, the prevalence rate of sarcopenia was less than 7 % under the age of 50, 18 % for ages 50–59, 33 % for ages 60–69, and 47 % for ages 70–85. Compared to the sarcopenia estimated by SM index, there was a higher prevalence of site-specific thigh sarcopenia observed in both sexes. These results suggest that site-specific thigh sarcopenia appears before it is able to be detected at the whole body level.

It is unknown if the site-specific muscle loss of ageing muscle is associated with accelerometer-determined daily step count and/or intensity of physical activity. The purpose of this study was to examine the relationships between accelerometer- determined physical activity and lower body muscle size in women.Forty-eight women aged 52 to 76 years had their muscle thickness (MTH) measured by B-mode ultrasound at seven sites on the anterior and posterior aspects of their upper- and lower-leg. Daytime physical activity was measured using an accelerometer on 30 consecutive days and the total duration of each level of exercise intensity (light-PA, moderate-PA and vigorous-PA), average step count, and physical activity-related energy expenditure were calculated.Age was inversely correlated with anterior 30% upper-leg MTH (r=-0.296, p0.05), but not with other measured MTH sites. Light-PA was not significantly (p0.05) correlated with measured lower body MTH. However, moderate-PA was correlated (p0.05) with lower-leg MTH, while vigorous-PA was correlated (p0.05) with lower-leg and anterior 30% upper- leg MTH. Following adjustment for confounding factors, the anterior and posterior lower-leg MTH was positively correlated (p0.05) with duration of moderate- PA and vigorous-PA, as well as average step count.Thus daily moderate and vigorous physical activity was associated with higher muscle mass in the lower leg, but not in the upper-leg muscle, suggesting that the site-specific upper-leg muscle loss may not be prevented or attenuated by daily physical activity.

Sarcopenia is observed as a site-specific loss of skeletal muscle mass, however, it is unknown whether the site-specific sarcopenia is associated with development of physical disability. The purpose of this study was to examine the relationship between age-related thigh muscle loss and gait performance. Fifty-three women aged 52-83 years had their thigh muscle thickness (MTH) measured by ultrasound at five sites on the anterior (30%, 50%, and 70% of thigh length) and posterior (50% and 70% of thigh length) aspects of their thigh. Maximum and normal walking speeds, zig-zag walking time, and maximal voluntary isometric knee extension and flexion strength were measured. Age was inversely correlated to the anterior and posterior MTH ratio (e.g., anterior 50%:posterior 70% MTH ratio [r=-0.426, p=0.002]), thus the site-specific muscle loss of the thigh was observed in the present sample. There were no significant correlations between the anterior/posterior MTH ratio and maximum and normal walking speeds. However, the ratios of anterior 50%:posterior 70% MTH (r=-0.430) and anterior 30%:posterior 70% MTH (r=-0.444) were correlated (p=0.001) to zig-zag walking test. After adjusting for age, height and weight, the anterior 30%:posterior 70% MTH (r=-0.292, p=0.040) was inversely correlated to zig-zag walking performance. Isometric knee extension strength was also inversely correlated to zig-zag walking. Our results suggest that an age-related loss of adductor/quadriceps muscles may be associated with a decrease in a relatively difficult task performance such as zig-zag walking.

The multidisciplinary, four-phase approach, which includes PSMF, BEM, and MPE is successful in treating mild, moderate, and severe degrees of childhood and adolescent obesity. The MPE program is appropriate for use with PSMF and BEM due to its progressive nature, variety of options, and moderate intensity level. In addition, the MPE program is of sufficient intensity, duration, and frequency to promote a significant increase in estimated aerobic capacity (VO2max) and to promote the maintenance of lean body mass and resting energy expenditure. The short-term intervention of PSMF, BEM, and MPE also results in an improvement in body composition, lipid profiles, and IGF-1 and T3 levels. The 1200-calorie balanced diet, MPE, and BEM also provide a successful method of weight maintenance in children and adolescents, as indicated by further improvement in body composition at the 26-week measure. Additional studies are needed to assess the contribution of exercise to the maintenance of lean body mass and resting energy expenditure in obese children and adolescents. In addition, it will be important to assess long-term weight maintenance in obese adolescents who effectively lose weight in this multidisciplinary program.

We compared the energy expenditure to walk or run a mile in adult normal weight walkers (NWW), overweight walkers (OW), and marathon runners (MR). The sample consisted of 19 NWW, 11 OW, and 20 MR adults. Energy expenditure was measured at preferred walking speed (NWW and OW) and running speed of a recently completed marathon. Body composition was assessed via dual-energy x-ray absorptiometry. Analysis of variance was used to compare groups with the Scheffe's procedure used for post hoc analysis. Multiple regression analysis was used to predict energy expenditure. Results that indicated OW exhibited significantly higher (p0.05) mass and fat weight than NWW or MR. Similar values were found between NWW and MR. Absolute energy expenditure to walk or run a mile was similar between groups (NWW 93.9 ± 15.0, OW 98.4 ± 29.9, MR 99.3 ± 10.8 kcal); however, significant differences were noted when energy expenditure was expressed relative to mass (MRNWWOW). When energy expenditure was expressed per kilogram of fat-free mass, similar values were found across groups. Multiple regression analysis yielded mass and gender as significant predictors of energy expenditure (R = 0.795, SEE = 10.9 kcal). We suggest that walking is an excellent physical activity for energy expenditure in overweight individuals that are capable of walking without predisposed conditions such as osteoarthritis or cardiovascular risk factors. Moreover, from a practical perspective, our regression equation (kcal = mass (kg) × 0.789 - gender (men = 1, women = 2) × 7.634 + 51.109) allows for the prediction of energy expenditure for a given distance (mile) rather than predicting energy expenditure for a given time (minutes).

Purpose:The aim of this investigation was to compare gender differences in physiologic and perceptual responses during a 1-h run at recent marathon pace and running economy at three speeds in recreational marathon runners.Methods:In a counterbalanced design, 10 men and 10 women completed a 1-h treadmill run and a running economy test. Treadmill speed for the 1-h run ranged from 141 to 241 m·min−1 and 134, 168, and 188 m·min−1 for running economy. Physiologic parameters (oxygen uptake, carbon dioxide production, pulmonary ventilation, and heart rate) and perceived exertion were measured. Repeated-measures ANOVA was used to compare any gender differences (P < .05) during the 1-h run and a two-way ANOVA was used to compare running economy. With this sample, estimated marathon energy expenditure, body composition, and maximal physiologic function was reported.1Results:With the exception of an allometric expression of VO2 (mL·min−1·kg BW−0.75), similar gender physiologic and perceptual responses were found during the 1-h run. Although not significant, the females exercised at a higher percent VO2max (8% to 9%) during the run. Similar gender differences were also noted during the running economy tests.Conclusions:Although the male runners completed a recent marathon significantly faster than the females, similar gender physiologic and perceptual responses were generally found during the 1-h treadmill run and the running economy tests.

The purpose of the study was to investigate the seasonal relationship of athletic amenorrhea and body composition in elite, adolescent, cross-country runners. The participants consisted of 28 female adolescent cross-country runners (mean age ± SD = 15.4 ± 1.5 years); 17 eumenorrheics and 11 amenorrheics. The participants’ body composition was measured pre- and postseason using dual-energy X-ray Absorptiometer (DXA). The eumenorrheics’ postseason BMD was significantly greater than the amenorrheics’ postseason BMD (F(1,54) = 16.22, p < .05, partial η2 = .231). The eumenorrheics’ postseason bodyweight (F(1,54) = 7.65, p < .05, partial η2 = .124), BF (F(1,54) = 8.56, p < .05, partial η2 = .137), and BMC (F(1,54) = 8.52, p < .05, partial η2 = .136) were significantly greater than the amenorrheic subgroup. There was also a significant seasonal increase in BMD (t(27) = –4.01, p < .05) for the overall group and the eumenorrheic subgroup (t(16) = –3.90, p < .05). Bodyweight best predicted BMD (F(1,26) = 46.434, p < .05, R2 = .641). In the study, athletic amenorrhea was highly associated with lower levels of BMD in the participants, and crosscountry running was highly associated with increased BMD.

This pilot study examined the feasibility of an interactive obesity prevention program delivered to a class of fourth-grade students utilizing daily e-mail messages sent to the students’ home computers. The study involved a single intact class of 22 students, 17 (77%) of whom submitted parental permission documentation and received e-mail messages each school day over the course of one month. Concerns regarding Internet safety and children’s use of e-mail were addressed fairly easily. Cost/benefit issues for the school did not seem prohibitive. Providing e-mail access to students without a home computer was accomplished by loaning them personal digital assistant (PDA) devices. In larger interventions, loaning PDAs is probably not feasible economically, although cell phones may be an acceptable alternative. It was concluded that this type of interactive obesity prevention program is feasible from most perspectives. Data from a larger scale effectiveness study is still needed.

This study examined energy expenditure and physiologic determinants for marathon performance in recreational runners. Twenty recreational marathon runners participated (10 males aged 41 +/- 11.3 years, 10 females aged 42.7 +/- 11.7 years). Each subject completed a V(.-)O2max and a 1-hour treadmill run at recent marathon pace, and body composition was indirectly determined via dual energy X-ray absorptiometry. The male runners exhibited higher V(.-)O2max (ml x kg(-1) x min(-1)) values (52.6 +/- 5.5) than their female counterparts (41.9 +/- 6.6), although ventilatory threshold (T-vent) values were similar between groups (males: 76.2 +/- 6.1 % of V(.-)O2max, females: 75.1 +/- 5.1%). The male runners expended more energy (2,792 +/- 235 kcal) for their most recent marathon as calculated from the 1-hour treadmill run at marathon pace than the female runners (2,436 +/- 297 kcal). Body composition parameters correlated moderately to highly (r ranging from 0.50 to 0.87) with marathon run time. Also, V(.-)O2max (r = -0.73) and ventilatory threshold (r = -0.73) moderately correlated with marathon run time. As a group, the participants ran near their ventilatory threshold for their most recent marathon (r = 0.74). These results indicate the influence of body size on marathon run performance. In general, the larger male and female runners ran slower and expended more kilocalories than smaller runners. Regardless of marathon finishing time, the runners maintained a pace near their T-vent, and as T-vent or V(.-)O2max increased, marathon performance time decreased.

Over 15% of children 6–11 yr old and adolescents 12–19 yr old in the United States are overweight (17). Among adolescent girls, the prevalence of overweight was reported as 15.5% in the 1999–2000 National Health and Nutrition Examination Survey (NHANES), compared with 9.7% in NHANES III (1988–1994) (17). Boys are generally more likely to be overweight and at risk than girls (11). However, African American girls have significantly higher rates of overweight than boys, and in Native American children no gender differences are apparent (6). In the simplest terms, overweight occurs when there is an imbalance between energy intake and energy expenditure. However, because physical activity is a highly variable component of energy expenditure, its relationship to weight status is not clearly understood, especially in female youth. Regardless, it is generally well accepted that lower than desirable energy expenditure, because of low physical activity, is a contributing factor to the recent increase in childhood overweight and obesity. Previous studies have examined the relationship between childhood weight or body composition and physical activity (9,10,15,16). Higher levels of physical activity were associated with lower levels of weight or body fat in several studies (9,16,24). Physical activity estimated by a questionnaire, but not activity energy expenditure (derived by doubly labeled water), was inversely related to body fat in children (10). The findings across studies likely differ because of differences in measurement techniques for body composition, physical activity and energy expenditure, and whether the focus is on an estimate of total physical activity or the energy cost of activity. Overweight/obesity can be determined by simple anthropometric measures (body mass and height) or by body composition techniques (e.g., skinfolds, bioelectric impedance, or dual-energy x-ray absorptiometry). Physical activity can be measured through self-reports (diaries and questionnaires) or more objectively, by accelerometry or doubly-labeled water. Accelerometers can quantify total activity over several days, and intensity can be characterized by utilizing previously established accelerometer thresholds for sedentary, light, moderate, and vigorous activity (26). Combining measures of body composition with accelerometry provides a unique way to explore relationships among body fatness, fat-free mass, and physical activity. Our purpose for the present analysis was to examine the nature of the relationship (linear, curvilinear) of body composition (size, fat mass, fat-free mass) to physical activity as assessed in sixth grade girls. Because physical activity is the primary outcome in the TAAG trial, we wanted to establish baseline relationships between physical activity (dependent variable) and body composition (independent variable). Specifically, we examined whether components of body composition were associated to moderate-to-vigorous physical activity (MVPA), vigorous physical activity (VPA), and MET-weighted physical activity using a large sample of girls from across the United States. This paper presents the baseline body composition and physical activity (as measured by accelerometry) of girls enrolled in The Trial of Activity for Adolescent Girls (TAAG), a multisite school- and community-based intervention designed to prevent the decline in physical activity in adolescent girls.

The purpose of this investigation was to examine the relationship between average weekly swimming distance and age with body composition in adult female endurance swimmers.Thirty-five women, aged 21-73 yr, volunteered to participate. Weekly swimming distance was determined from a self-reported exercise log. Body composition was estimated by dual-energy x-ray absorptiometry (DXA), waist circumference, abdominal sagittal diameter, and skinfold thickness measures. Associations between swimming distance and age with body composition were examined using regression analysis.Swimming distance had shared variances as follows: 23% with percent body fat, 26% with waist circumference, 20% with abdominal sagittal diameter, and 20%, 24%, and 22% with subscapular, suprailiac, and triceps skinfolds, respectively. Abdominal sagittal diameter was the only adiposity measure demonstrating a stronger relationship with age (R2 = 0.29, P = 0.00) than with swimming distance (R2 = 0.20, P = 0.03). Bone mineral content was linearly related to swimming distance and age having a negative association with age (r2 = 0.18, P = 0.01) and a positive one with swimming distance (r2 = 0.12, P = 0.05). In addition, there was a negative linear association observed between swimmer age and bone mineral density (r2 = 0.12, P = 0.05).In these female adults, endurance swimming was mildly associated with body adiposity. Age was not associated with body fat mass independently from swimming activity except with that measure reflecting abdominal visceral fat deposits. These data suggest that greater fat mass in female swimmers is more strongly related to lower levels of exercise than to age but that there is an additional influence of age on fat accumulation in the intra-abdominal area of the body.

Researchers have investigated the effect of exercise on reducing subjects' responsiveness to stress. Results from the initial studies were positive, yet these studies often did not use objective measures of fitness. This investigation applied more rigorous methodology than past experiments to assess the relationship between fitness and reactivity to stress. Maximal oxygen consumption was measured to indicate the fitness of recreational cyclists who were then exposed to three stressful situations (mental subtraction, speech preparation, and the cold pressor test). Heart rate, frontalis electromyographic (EMG) levels, and self-report of tension were monitored during the stress-inducing tasks. Physical fitness was significantly related to heart rate taken during the subtraction and cold pressor tasks, with EMG during subtraction, and with self-report during all three stressor tasks. These results further support the hypothesized association of physical fitness and reducing response to stress.

Aerobic forms of exercise have been suggested as one approach to reducing the costly effects of excessive or chronic stress, yet the results of some studies related to this assumption have been mixed. The purpose of this study was to estimate the correlation between emotional states and fitness level among 8 women and 9 men who were recreational cyclists. Fitness was determined by cycle ergometric testing (VO2 max). Psychometric measures included the short version of the Beck Depression Inventory, the internal portion of the Multidimensional Health Locus of Control Scale, Spielberger's State-Trait Anxiety Inventory, and the Self-control Questionnaire. Significant correlations were observed between fitness and the depression scores, internal locus of control, and self-control measures. These results tend to support previous findings regarding the possible link between physical fitness and improved emotionality.

A comparison of pulmonary, cardiovascular and metabolic responses was made in 32 subjects consisting of 11 able-bodied, 8 paraplegics (T4-L3 lesions) and 13 quadriplegics (C5-C8 lesions) during maximal arm cranking exercise. A progressive continuous arm cranking test, modified for each group, was employed to elicit maximal responses with pulmonary and metabolic determinations made with open circuit spirometry and selected cardiovascular measurements made by impedance cardiography. Additionally, non-exercise static and dynamic lung function assessments were made. Quadriplegics had significantly lower (p less than 0.05) tidal volumes, vital capacities, forced expiratory volumes at 1 seconds, and maximal breathing capacities than the other two groups. The mean peak VO2 during maximal arm cranking was 28.2, 25.3 and 12.0 ml/kg.min for the able-bodied (AB), paraplegics (PP) and quadriplegics (QP), respectively. Furthermore, reduced cardiovascular function was observed in the QP as evident in the low peak HR (109 b/min), peak SV (52 ml/b) and peak Q (5.7 l/min). Values for the QP were 64% and 64% peak HR, 89% and 50% peak SV and 54% and 33% peak Q of values observed for the PP and AB groups, respectively. The peak SV and Q values were significantly lower (P less than 0.05) for the PP group when compared with the AB group. Although not statistically significant the estimated a-v O2 difference was higher for both spinal cord injured groups (14.0 and 14.6 ml O2/100 ml, PP and QP respectively). The impaired work capacity and reduced oxygen transport and utilisation of the QP group can be attributed to impaired sympathetic cardiac stimulation and a smaller available active muscle mass.

The purpose of this study was to examine the effect of endurance arm training on metabolic and circulatory function during arm and leg exercise. Thirty-eight females (aged 18 to 35 yr) participated in the study, with 19 subjects in the training group and 19 in a control group. Both a specific and general training response was observed at the conclusion of the 5-wk training period. As a result of training, during peak arm exercise, significant increases (P less than 0.05) were observed for oxygen uptake (VO2), ventilation, cardiac output, stroke volume, arterial-venous oxygen difference, cumulative work, and total performance time. During peak leg exercise following arm training, significant increases (P less than 0.05) were observed for VO2, ventilation, cardiac output, cumulative work, and total performance time. Standardized partial regression coefficients were used to examine the relative influence of the metabolic and circulatory components which define VO2. Prior to training during arm work, the arterial-venous oxygen difference accounted for the largest proportion of variance in VO2; but after training, stroke volume contributed the largest portion of variance. On the other hand, during leg exercise, stroke volume accounted for the largest portion of variation in leg VO2 both before and after arm training. The data suggest that endurance arm training as prescribed in this study elicits significant circulorespiratory function adaptations to support improved performance in both arm and leg work. Further, the findings suggest both a specific and general training effect, with the more dominant effect specific to arm work.(ABSTRACT TRUNCATED AT 250 WORDS)